Many offshore oil and gas fields are developed and produced using a multi-well platform. In general a template is placed on the seabed, which comprises slots and a well is drilled through each slot. It is not uncomment to have 10 to 20 wells drilled from a single template. Each well will be drilled to hit a particular reservoir target or targets. The trajectory of the wells can be very different but care is taken to make sure that the wells do not collided with each other. In some cases, these wells are drilled individual at some distance between them or other templates. There wells, often called satellite wells, have individual well heads that are connected into the production system via long flow-lines to a collection manifold which in turn is connected to the production platform or facility.
The production from these wells is often co-mingled and processed on a single production platform or facility. In the case of offshore field development, these production platforms can be floating, e.g., FPSO (Floating Production Storage and Offloading) or permanent platform structures. Such productions units are very expensive systems and platform space comes at a premium. As an illustration, costs can be $100,000 per tonne of payload and $25,000 per square meter of facility area. As a result, reducing the weight and size of the required process equipment is very important. In addition, consumables required for the process require storage space, which adds to their purchase price and so increases the overall cost of their use. Again, keeping these to a minimum or ideally eliminating the need for additional products will allow for a more cost effective process requiring less platform space (and load capacity).
Generally the production from a well or group of wells will comprise oil, gas, water and solid particles (usually sand). In the industry these are often referred to as different phases, that is, there are four phases in the production flow. Before oil and/or gas can be exported from a production facility to a refinery or storage facility, it must be first cleaned of any solids and water. It is also beneficial to separate the gas from the oil so that there are two independent product streams, that is, gas and oil. Water and solid particles are considered to be by-products that need to be disposed of. Usually the solids need to be cleaned of any traces of oil so that they can be disposed of without damage to the environment. Therefore the production flow is best separated into its four phases. Today this often requires a lot of equipment to carry out these separations in sequential steps. In particular, solids are removed first using one processing step followed by water removal and finally gas and oil. As a result, a large footprint or platform area is required which increases the overall cost of the system. This can significantly increase the construction cost of the production facility or platform.
The present inventors have worked to establish technical solutions to the above restrictions associated with technology presently used in the industry or disclosed in the prior art.